1. Field of the Invention
The invention relates to a display system for a vehicle, in particular commercial vehicle, by means of which display system images of the vehicle environment can be displayed in a vehicle interior, e.g. in a driver's cabin of a commercial vehicle, so that they are visible to the driver. Such display systems which are, inter alia, used as mirror replacement systems or, additionally to the exterior mirrors of a vehicle, serve for displaying the situation in the vehicle environment in specific driving situations, or permanently, and as ergonomically as possible to the driver, thus contributing to an increased traffic safety by providing the driver of the vehicle with a good overview of the traffic situation around the vehicle and of possible dangers.
2. Description of the Related Art
Mirror replacement systems and other camera-monitor-systems and display systems, respectively, for vehicles are known in the prior art. These systems usually comprise a capturing unit, e.g. a camera, by means of which at least a field of view around the vehicle can be captured and image data of the field of view can be acquired, a calculation unit which processes the image data and provides the same for display on a display unit like, for example, a monitor, or for projection on structural parts of the vehicle. The captured fields of view around the vehicle may also include legally prescribed fields of vision, which, for Europe, are prescribed by ECE regulation R 46.
It is, inter alia, known to use monitors with so-called split screen view where a plurality of images, which images are often different and possibly captured by different capturing units, are shown on the same monitor on different monitor portions. Here, the individual image portions are separated by separating lines or separating portions which may be monochromatic or varicolored and usually have a width of one to several pixels.
In other systems, which are inter alia used for so-called driver assistance systems, it is also known to superimpose warning frames on the image portions in case the calculation unit recognizes an obstacle or hazard area in the captured image by analysing the image. Thus, it can be warned of a possible hazard by highlighting said hazard by means of the warning frame. It is further known to also overlay other graphics, e.g. partially transparent graphics.
In the known prior art display systems, it is further possible to modify the display, e.g. in which size an image of a certain capturing unit is displayed on a display unit, dependent on external signals, e.g. the steering angle or the driving condition of the vehicle, e.g. forward driving or reversing. When acquiring a steering angle that does not correspond to straight forward driving, for example, it is known to display the side area next to the vehicle in an enlarged or otherwise highlighted manner.
Although, in the known display systems, overlaying or superimposing of separating lines or warning frames and graphics, respectively, may possibly be effected dependent on the driving situation, it is not effected dependent on the image characteristics of the image to be displayed, which is directly adjacent to the separating line or frame and graphic, respectively. Consequently, when the characteristics of the image content directly adjacent to the separating line or superimposition substantially correspond to the characteristics of the separating line or superimposition, the latter may no longer be recognized by the driver. If, for example, black separating lines are used in images captured at night, it is hard to distinguish between image and separating line.
US 2013/0307985 A1 refers to a vehicle driving assist device which can clearly display super-imposing guidelines on an image captured from the surrounding area of a vehicle. The modified image is displayed on a display unit. For this purpose, a color attribute detection means detects a hue or the brightness of the captured image area on which a guideline is superimposed. Dependent on the detection, a color combination pattern setting means or a brightness setting means sets a color combination or brightness, respectively, of the overlayed guidelines and compares contrast or brightness of the captured image area to hue or brightness of the guideline and, if these are similar or identical, sets a changed color combination pattern for the guide-lines at least in parts of the image, in which hues or brightness are identical or approximate.
US 2013/0176329 A1 refers to a surrounding image display system, in which an image captured by a camera is processed by a processing unit and a frame border is overlayed to the image. The frame border includes a frame border portion drawn in a first color and a second frame border portion drawn in a second color different from the first color.
JP 200123988 A2 refers to a vehicular circumference viewing device wherein a partitioning line between two displayed images consists of black and light blue.